If utility executives pull the plug permanently on the San Onofre nuclear plant, the list of losers is long: consumers face nearly $3 billion in costs, the risk of blackouts will rise, and air quality will suffer.

Yet Southern California Edison, the giant utility that botched the nuke’s retrofit and caused its shutdown, seems remarkably confident that its investors will emerge relatively unscathed. Welcome to the great coin toss of regulated monopolies, where utility shareholders typically win on heads, and consumers lose on tails.

Given that Edison led the project that essentially installed faulty radiators in its nuclear reactors — after deciding to use an untested new design from a contractor — the odds for consumers may be better this time, in what’s shaping up as the biggest regulatory struggle in a decade.

The referee is the California Public Utilities Commission, which has an almost unblemished record of siding with utilities – and against consumers – in disputes about who pays for investments in generating electricity. But Gov. Jerry Brown appointed four of five commissioners. He may be susceptible to public pressure.

Meanwhile, the clear winners include the independent generators and Wall Street trading firms raking in surprise profits in Southern California’s generally depressed power market, as utilities spent $516 million last year just to buy the electricity to replace San Onofre’s lost output. SDG&E, which owns 20 percent of the plant, spent $72 million of that total.

And we are all safer with the plant shut down, given that its twin nuclear reactors are situated in one of the nation’s major population and economic centers. Experts argue about the level of risk of catastrophe, but there is a risk. People who’ve lobbied for years to retire San Onofre are feeling pretty good right now.

Last week Ted Craver, the CEO of Edison’s parent company, told investors that he is pondering whether to shut the nuclear plant down for good if federal regulators don’t quickly approve his engineers’ plan to restart one of the plant’s two reactors for five months at 70 percent power to see if it breaks.

“Without a restart of Unit 2, a decision to retire one or both units would likely be made before year-end 2013,” Craver said in a call with analysts.

This was very big news. It was the first time anyone at Edison has publicly discussed giving up on the crippled nuke, which until January 2012 provided 20 percent of San Diego County’s electricity supply.

But such shutdown talk was also bizarrely incomplete, for reasons that are clear to anybody who has depended on an old car and worried about the inevitable repair bills.

Let’s say the cooling system died, and you paid $1,000 to replace it. It was a tough decision, because the car was only worth $2,000 to begin with. Now the car has broken down again, and the mechanic says he doesn’t quite know how to fix it.

Should you tow it to the junkyard and buy another car? Or risk fixing it again? That answer has nothing to do with your last repair; it depends on how much the new repair will cost you – and Edison will say nothing publicly about how much it might cost to fix its nuke. It wants permission from the Nuclear Regulatory Commission to do some testing for five months, but it has no plan to fix its power plant, let alone give an estimate of the eventual cost.